The 20 types of force (according to physics)

A review of the different types of strength from the different facets of physics.

The concept of strength has a lot of denotations in different fields, being in some synonyms of strength both physically and mentally, resilience and resistance to events.

But beyond that, we also call force one of the main magnitudes of physics, studied from basic physics to the most complex branches of science, and involved in a large number of phenomena, actions and reactions.

Thus, at the level of physics we can speak of different at the level of physics we can speak of different types of forceabout which we are going to make a brief mention in this article.

What do we call force?

Before starting to talk about the various typologies or categories that have been established when analyzing different types of strength, it is necessary to establish a brief definition of the concept.

In a generic way we can define force as a physical magnitude of vectorial typeIt is associated with and considered the cause of the capacity to generate a displacement or movement with acceleration on the part of a body or object, a modification in its structure or even its state of rest when, in order to reach this state, a resistance to another force must be exerted. In order to be correctly defined, it should be noted that every force has a point of application, a direction and a specific intensity that will determine the final behavior of the object.

As a magnitude the force has a unit of measurement, the Newton (in honor of Isaac Newton, who is considered the first to establish a mathematical formula for its calculation), which refers to the amount of force necessary to generate an acceleration of one meter per second squared in a body of one kilogram of mass. There are also other units of measurement, such as the dyne.

Types of force

It is possible to classify the types of force according to different criteria. Let's see them.

1. According to specific parameters

We can find classifications made on the basis of aspects such as their permanence, the existence or not of a direct contact between the bodies or the way they act. Examples are the following types of force.

1.1. Fixed forces

Fixed or permanent forces are understood to be all those forces inherent to the body or object in question itself and deriving from its structure or configuration, and from which it is not possible to escape. One of the most easily visible of these is weightOne of the most easily visible is weight, the product of the mass of the body and the gravitational attraction to which it is subjected.

Variable forces

Also called intermittent, are those forces that are not part of the structure of the object or body in which the movement or change occurs but that comes from other bodies or elements. An example would be the force applied by a person to a car to move it.

1.3. Contact

Contact forces are understood as all those forces that are characterized by the need for contact between bodies or elements in order to generate a movement or structural change. These are the forces traditionally worked on by classical mechanicsas we will see later.

1.4. At a distance

Contrary to the previous case, the forces at a distance are all those in which it is not necessary for there to be contact between the bodies to achieve an alteration of the structure or a displacement of the bodies. An example of this would be electromagnetism.

1.5. Statics

All those forces that do not vary in intensity, direction or place, remaining practically constant whenever they exist, are called static. An example would be the force of gravity.

1.6. Dynamic

The dynamic forces are all those in which the general values that are part of the force vary constantly and abruptlychanging its direction, place of application or intensity.

1.7. Action forces

This name is given to those forces that are applied to an object with the purpose of displacing it or modifying its structure, not arising from the object itself but from some external element. The fact of pushing something would imply to be applying a force of action.

1.8. Reaction

All those that are generated by the body itself in response to the application of a force are denominated as such. in response to the application of an external forcefrom a given point of application. In the previous case, the moved body would be exerting a reaction force towards us.

1.9. Balanced

These are understood as those forces that oppose each other having equal intensity but whose directions are totally opposite. whose directions are completely oppositeThis causes the body in question to remain in a specific position. This type of force would be exemplified by any object lying still on the ground or by two people of the same strength pushing each other at the same time.

1.10. Unbalanced

We refer to those forces that when applied on a specific body generate its movement1.10. Unbalanced We refer to those forces which, when applied on a specific body, generate its movement, since there is no equilibrium or sufficient opposing force to prevent it.

2. In classical mechanics: contact forces

There are many and diverse types of forces that we can find in nature, but generally when the concept of force begins to be studied physically, it is usually used in the context of classical mechanics, referring to a type of forces called contact forces. Within these we can find the following types of force.

2.1. Normal forces

A normal force is understood as a force that is exerted by the interaction between two bodies in contact with each other.The force applied to an object, such as an object and the ground, exerts a force reactive to the force of the weight which would go in the opposite direction to that of the weight.

2.2. Applied

An applied force is a force that one body exerts on another and that causes an accelerated motion or a change in the structure of the object. It is a direct contact force.

2.3. Friction

Friction or frictional force is the force that arises when two bodies come into contact with each other and that direction directly opposite to the applied or normal force.. For example, when pushing an object it offers a resistance produced to a large extent by the frictional force against the ground.

Another analogous form of this type of force, which is sometimes classified independently, is that of air resistance. This force is the one that explains for example that two objects of the same mass launched at the same time from the same height can take different times to reach the ground (air friction), or that an object pushed down a slight slope can end up slowing down.

2.4. Elastic

We call elastic force that which is produced when a surface or object is held in a position of non-equilibrium by a given force, appearing as a reaction that seeks to restore that initial position or equilibrium. That is to say, it is the one that occurs when a body subjected to a force that has deformed it tries to return to its original state. A typical example can be found in springs, springs or stretched rubber bands that try to return to their original position.

2.5. Tension

This is a peculiar type of force, characterized by being able to transmit a force between different bodies and is generated when two opposing forces pull a body in opposite directions without breaking it. pull a body in opposite directions without breaking it.. It can be used to generate systems that distribute the force to be applied to generate the movement. The tension force is the force that allows us to use, for example, pulleys to move heavy objects.

2.6. Inertia force

Inertia force or fictitious force is the force with which a body is moved by the resultant of the forces that have been previously applied to it even when the body or object that has generated the force has ceased to apply it directly. It is the force with which a body maintains its state of motion, in the same direction of acceleration. This is what happens, for example, when in the event of a collision or sudden deceleration of a car, the body of the occupants tends to project in the same direction as that of the vehicle. tends to project in the same direction as the vehicle. direction in which the vehicle was moving.

3. Fundamental forces

In addition to those of classical mechanics and relating to macroscopic bodies, we can find other major forces that refer to the relationships that have the particles of matter to each other or the existence of forces at a distance, their study being mostly a product of modern physics and allowing to explain much of the above.

3.1. Gravitational force

We call gravitational force to that force of attraction existing between the objects between objects and whose intensity depends on their masses and the distance between them.. The most studied gravitational force is that of the planet itself, which attracts the bodies that exist on it towards its surface, being one of the best known forces at a distance. It is also the force that makes the planets orbit around the stars. It is also important in quantities such as weight.

Electromagnetic force

Although in the past we spoke separately of the magnetic and electrostatic forces, the progressive study of the properties of these forces has shown that they are in fact interrelated.

This is the force through which electric particles are attracted or repelled by other charged particles with the opposite sign (magnetic force). either with the opposite sign (attractive force) or with the same sign (repulsive force). When these relationships occur in moving particles, electromagnetic fields are generated.

Weak nuclear force

Probably some of the most difficult forces to understand for those not versed in physics is the nuclear force. In the case of the weak nuclear force, we are dealing with a type of force that allows for the decay of neutrons and radioactivity. allows neutron decay and radioactivity to occur.. In addition to generating forces of attraction and repulsion, it allows a particle to change.

3.4. Strong nuclear force

Coming from particle physics, the strong nuclear force is the one that allows two particles that by electric charge should repel each other to remain united, something that allows the existence of a proton nucleus. the existence of a nucleus of protons in most molecules. in most molecules.